Prosthetic device, system and method for increasing vacuum attachment

ABSTRACT

A prosthetic system includes a pump mechanism operatively connectable to a prosthetic foot. The pump mechanism has a housing defining first and second ports, a membrane having an outer edge portion secured to the housing, and a fluid chamber with a volume defined between the housing and a first side of the membrane. The fluid chamber is in fluid communication with the first and second ports. A connector is attached to a second side of the membrane opposite the first side. The connector operatively connects the membrane to the prosthetic foot such that when no weight is placed on the prosthetic foot the volume of the fluid chamber is zero or near-zero and when weight of a user is placed on the prosthetic foot the membrane deforms to expand the volume of the fluid chamber.

FIELD OF ART

The disclosure relates to the field of prosthetic devices, and moreparticularly to a prosthetic device, system and method for increasingvacuum in a vacuum assisted suspension system.

BACKGROUND

With advancements in prosthetic components, improved suspensionsolutions have become a pressing need. Elevated vacuum suspension hasbeen around for nearly a decade, and improves proprioception and volumecontrol. The concept is well accepted and has gained many users.

Many known elevated vacuum solutions on the market rely solely onsleeves or reflecting liners for placement over a socket to achieve anairtight seal necessary for an effective vacuum. This mode of sealing,particularly sleeves, adds to material thickness over the knee andconstrains knee bending dramatically for trans-tibial amputees.

A vacuum in the sense of elevated vacuum solutions refers to creatingpressure significantly lower than atmospheric pressure. In prostheticsystems, a vacuum is not applied directly to the skin, but typicallybetween the hard socket and the skin interface. The vacuum system isadapted to stabilize soft tissue volume at the residuum that the linerand hard socket surround and maintain more effective suspension of aprosthetic system.

A significant drawback to known elevated vacuum solutions is they failto adapt to limb volume change which occurs particularly when a user iswalking. Yet another drawback is that many known systems have a tendencyto lose suction due to the method used to seal the socket and hence thevacuum formed. Many of such vacuum systems are bulky and significantlycontribute to the weight of the prosthetic device, wherein the hardsocket may be oversized to accommodate vacuum chambers, or additionalattachments are used to supply or assist in vacuum generation.

In sleeve based systems, a sleeve is applied at the proximal end of thehard socket and the vacuum is often formed along the entirety or nearentirety of residual limb covered by the hard socket. The vacuum isformed along the length of the covered residual (i.e., “above-knee”vacuum systems) and does not account for areas of the residual limb moreor less prone to volume change. When the sleeve is removed, the seal isbroken and the vacuum is lost. While valves may be used in combinationwith vacuum suspension, these solutions often lack means to quicklyrelease the vacuum.

There is a need for a prosthetic device, system and method that providesfreedom of vacuum suspension for a prosthetic system with no sleeve.There is also a call to provide a prosthetic device, system and methodto minimize changes in the volume of a residual limb with vacuumsuspension, providing secure vacuum without losing suction andconfidence to the user over a period of use. There is a demand forapplying a vacuum where it is needed, while still stabilizing volume andmaintaining vacuum suspension. It is desirable for prosthetic devices todraw a vacuum while being lightweight and streamlined.

SUMMARY

Embodiments of the prosthetic device, system and method provide thesecurity and freedom of vacuum suspension without the sensation andrestrictions of a sleeve, or the accompanying bulk and complicatedfeatures and attachments. Without a sleeve, range-of-motion can be lessrestricted and the vacuum can be released quickly and easily by arelease valve.

The embodiments address volume fluctuation for effective volumestabilization. The embodiments have a capacity to create a distal vacuumand stabilize soft tissue volume and maintain effective suspension. Bylocating distal suspension, the embodiments avoid the risk of proximalvacuum leakage and any puncture issues that may arise with full vacuumsystems.

The embodiments are preferably but not limited to forming a distalvacuum around the distal part of the limb to stabilize volume whilecreating effective and sleeveless vacuum suspension. The embodimentsrely on the understanding that the distal end of the limb, where thereis typically more soft tissue, is the area most susceptible to volumefluctuations and the area which requires efficient stabilization tomaintain good suspension and prosthetic function. The area closer to theknee containing bones and tendons is relatively stable over the day anddo not fluctuate significantly in volume, thereby removing the necessityfor negative pressure to be formed throughout the entirety of theprosthetic socket.

The embodiments comprise a mechanical vacuum pump or mechanism providingvacuum assisted suspension by generating negative pressure inside aprosthetic socket worn over a residual limb, and reducing slidingmovement between the liner and the socket. The function of theembodiments is automatic as it is activated during gait; the weightplaced on the heel of a prosthetic foot expands the vacuum pump whichefficiently draws air out from the socket in each step, and expels itinto the atmosphere during swing phase as the reservoir compressesagain. The pump mechanism creates a negative pressure inside the socket,resulting in secure and reliable elevated vacuum suspension. The vacuumassisted suspension enables intimate suspension as the negative pressureformed inside the socket holds the liner and residuum firmly against thesocket wall.

According to an embodiment, a prosthetic system has a prosthetic foot, apump mechanism defining first and second sides, a first member connectedto the prosthetic foot and the first side of the pump mechanism, and asecond member carrying the pump mechanism and engaging the prostheticfoot. The second side of the pump mechanism is connected to the secondmember. The first and second members are movable relative to one anotherupon movement of the prosthetic foot such that the pump mechanism variesin volume as the first and second members move relative to one another.

The prosthetic system includes a prosthetic socket in fluidcommunication with the pump mechanism and connected to the prostheticfoot. A tube connects an interior of the prosthetic socket to a firstport of the pump mechanism. The pump mechanism is arranged to draw airfrom the prosthetic socket interior upon expansion of the pumpmechanism. The pump mechanism has a second port including a one-wayvalve arranged for expelling air drawn from the prosthetic socketinterior.

A suspension liner has a seal component adapted to engage at least aninterior wall of the prosthetic socket. The seal component is located ona distal end of the suspension liner and circumferentially engages theinterior wall of the prosthetic socket defining an interior of theprosthetic socket. The area distally below the seal component forms avacuum zone within the prosthetic socket. The tube connects theprosthetic socket interior within the vacuum zone to the first port ofthe pump mechanism.

A valve may be secured to the socket and connect the prosthetic socketinterior to the tube. The valve is arranged to permit expulsion, vacuumbypass and vacuum release.

A second end of the first member is secured to the second member, andthe first member has a first end secured to the prosthetic foot, and asecond end extending freely over a surface of the prosthetic foot. Acompressible heel element may be connected to the second member andextend between upper and lower sections of the prosthetic foot.

According to the embodiments of the prosthetic system, a method forusing the embodiments provides vacuum suspension. The method may includethe steps of locating the seal component at a distal area of thesuspension liner, forming a vacuum zone at a distal area of theprosthetic socket from the seal component to the distal end of theprosthetic socket, connecting the pump mechanism to the vacuum zone, andarticulating the prosthetic foot to actuate the pump mechanism to draw avacuum from the vacuum zone during gait of a user.

The method may further comprise the steps of connecting the pumpmechanism to the prosthetic socket via a tube arranged for drawing avacuum from the interior of the prosthetic socket and through a firstport on the pump mechanism depending on movement of the prosthetic footduring gait, and expelling air drawn by the pump mechanism through asecond port on the pump mechanism on movement of the prosthetic footduring gait.

In another embodiment, a prosthetic device is arranged for securing to aprosthetic foot. The prosthetic device includes a pump mechanismdefining first and second sides, a first member arranged for securing toa prosthetic foot and connected to the first side of the pump mechanism,and a second member carrying the pump mechanism and engaging theprosthetic foot. The second side of the pump mechanism is connected tothe second member. The first and second members are movable relative toone another upon movement of the prosthetic foot such that the pumpmechanism varies in volume as the first and second members move relativeto one another.

The pump mechanism includes first and second ports, where the first portis arranged to draw fluid due to the increase of volume of the membrane,and the second port includes a one-way valve is adapted to expel fluidupon relaxation of the membrane.

The first side of the pump mechanism may be pivotally coupled to thefirst member.

A compressible heel element may be securable to a prosthetic foot, andthe first member extends over the heel element. A connector secures to afirst side of the pump mechanism to the first member.

In an embodiment of the pump mechanism, it may include a housing havingfirst and second ports, a fluid chamber with a volume defined by anenclosure at least partially formed from a flexible material where anupper side of the fluid chamber is in fluid communication with the firstand second ports, and a connector connected to a lower side of theenclosure. A portion of the enclosure is shifted to increase the volumeof the fluid chamber.

The pump mechanism may include a tube connected to the first port. Thefirst port is arranged to draw fluid through the tube due to theincrease of volume of the fluid chamber. The second port may include aone-way valve. The increase in the volume of the fluid chamberpreferably occurs by deforming or extending a wall of the enclosure.

The enclosure may have two opposing walls connected by at least one sidewall. The connector is formed of an insert attached to the enclosure,and may include a fastener securing to the insert. In an alternativeembodiment, the connector has a pivotable coupling part.

In a variation, the housing includes an arm section having first andsecond ends, a plate section extending from the first end of the armsection, and a bumper secured to a second end of the arm section. Thefirst and second ports are located over the plate section of thehousing. The bumper may include a roller element.

The pump mechanism may be combined in a prosthetic system including aprosthetic component. The pump mechanism includes a connector connectedto a lower side of the enclosure and the prosthetic component, such thata portion of the enclosure is shifted due to movement of the prostheticcomponent to increase the volume of the fluid chamber.

The prosthetic component may be a prosthetic foot. In an embodiment, afirst member connects the pump mechanism to a portion of the prostheticfoot. The first member has an extending section movable relative to theprosthetic foot such that when weight of a user is applied to theprosthetic foot causing motion of the member, a portion of the enclosureis shifted to increase the volume of the fluid chamber. The first membermay secure to a proximal end of the prosthetic foot, and the extendingsection extends freely over at least an ankle portion of a front surfaceof the prosthetic foot.

The embodiment may include a second member connected to the first memberand extending thereover. The pump mechanism is preferably mounted to thesecond member and the connector mounted to the first member. The fluidchamber changes in volume between the first and second members uponaction of the prosthetic foot.

According to a variation, the housing of the pump mechanism furtherincludes an arm section having first and second ends, a plate sectionextending from the first end of the arm section, and a bumper secured toa second end of the arm section. The bumper is arranged to engage theprosthetic foot.

Embodiments of the disclosure are preferably arranged to apply anelevated vacuum with a sealing suspension liner, for example a sealcomponent extending from the suspension and arranged to engage an innerwall of a socket. The embodiments preferably employ a single pumpmechanism mounted on and having minimal impact on the function of aprosthetic foot.

BRIEF DESCRIPTION OF THE DRAWINGS

The prosthetic device is described referring to the accompanyingdrawings which show preferred embodiments according to the devicedescribed. The device, system and method as disclosed in theaccompanying drawings are illustrated for example only. The elements andcombinations of elements described below and illustrated in the drawingscan be arranged and organized differently to result in embodiments stillwithin the spirit and scope of the device described.

FIG. 1 shows a side view of an embodiment of the prosthetic device.

FIG. 2 shows a side view of another embodiment of the prosthetic device.

FIG. 3 shows an embodiment of the prosthetic device with a pumpmechanism.

FIG. 4A shows a view of an embodiment of the prosthetic device havingtwo plates from the front.

FIG. 4B shows a cross-section of the embodiment in FIG. 4A.

FIG. 5A shows another embodiment of the prosthetic device whichcompresses a housing of a vacuum pump to actuate the pump.

FIG. 5B shows a cross-section of the embodiment in FIG. 5A.

FIG. 6 shows an embodiment of the prosthetic device having a cylinderblock in the heel area of a prosthetic foot.

FIG. 7A shows another embodiment of the prosthetic device.

FIG. 7B is a cross-sectional side view along line VIIB-VIIB of theembodiment shown in FIG. 7A.

FIG. 7C is a detailed view of the heel element of the embodiment shownin FIG. 7A.

FIG. 8 is an elevational view showing a vacuum suspension systemincluding the embodiment of FIG. 7A.

FIG. 9 is a perspective view of a tri-function valve in the vacuumsuspension system of FIG. 8.

FIG. 10 is an exploded view of the tri-function valve of FIG. 9.

FIG. 11A is a schematic view of the tri-function valve of FIG. 9 inexpulsion.

FIG. 11B is a schematic view of the tri-function valve of FIG. 10 invacuum bypass.

FIG. 11C is a schematic view of the tri-function valve of FIG. 9 inrelease.

FIG. 12 is another embodiment of the prosthetic device.

FIG. 13A is a sectional view of the pump mechanism in FIG. 12 in a firstconfiguration of the prosthetic foot.

FIG. 13B is a sectional view of the pump mechanism in FIG. 12 in asecond configuration of the prosthetic foot.

FIG. 14 is a disassembled view of the pump mechanism in FIG. 12.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

A better understanding of different embodiments of the prosthetic devicemay be gained from the following description read with the accompanyingdrawings in which like reference characters refer to like elements.

While the disclosure is susceptible to various modifications andalternative constructions, certain illustrative embodiments are in thedrawings and will be described below. It should be understood, however,there is no intention to limit the disclosure to the specificembodiments disclosed, but on the contrary, the intention covers allmodifications, alternative constructions, combinations, and equivalentsfalling within the spirit and scope of the disclosure and defined by theappended claims.

It will be understood that, unless a term is expressly defined in thisdisclosure to possess a described meaning, there is no intent to limitthe meaning of such term, either expressly or indirectly, beyond itsplain or ordinary meaning.

Any element in a claim that does not explicitly state “means for”performing a specified function, or “step for” performing a specificfunction, is not to be interpreted as a “means” or “step” clause asspecified in 35 U.S.C. §112, paragraph 6.

The embodiments of a prosthetic device will be described which form partof a vacuum system. A vacuum pump mechanism having a fluid connectionwith a socket assists in creating a vacuum between a residual limb andthe socket by pumping fluid out of the socket. The fluid is pumped outof the socket when the user puts his weight on a prosthetic foot such asupon a heel strike. The compressive force of the heel strike causes thepump to increase the volume of a fluid chamber in the pump. The increasein volume of the pump draws in fluid from the vacuum space between theresidual limb and the socket of a prosthetic limb. In this manner, thepump decreases the air pressure within the vacuum space causing a vacuumeffect.

After the compressive force is removed during toe-off and the swingphase of gait, the volume of the fluid chamber in the pump is decreased.The connection between the vacuum space and the pump may have a one-wayvalve, so all of the air within the volume of the pump is expelled outof an outlet to another space or to atmosphere. The outlet is providedwith a one-way valve so the vacuum space is the only source of air.

This method of producing a vacuum effect in the prosthetic socket isadvantageous over prior methods of compressing the pump to expel air anddecompressing the pump to draw in air. The method described achievessmaller fluctuations in air pressure than the prior method, so thedifference between the greatest pressure and lowest pressure in thevacuum space is less in the method described compared to the priormethod.

The efficiency of the pump is determined partially by how effectivelythe volume of the fluid chamber is reduced. Since the pump returns tothe original state of zero or near-zero volume at the beginning or endof each cycle, the volume of the fluid chamber is determined by thecompressive force applied to the pump. In the method described, allfluid drawn into the pump is expelled afterwards fully utilizing eachcycle. The method described may be implemented using a pump that has nospring type elements which may affect the bio-mechanical function of theprosthetic device.

In the prior methods, the system relies on a complete compression of thepump in expelling air in each cycle to use the pump to its maximumcapacity. It is difficult for complete compression to occur in everycycle using the gait of a user as the compressive force since the impactand displacement of the pump is not consistent and varies between users.

The vacuum suspension system also reduces volume fluctuations of theresidual limb and allows for increased proprioception and reducedpistoning since there is a better attachment between the socket and theresidual limb. It may also be beneficial to produce hypobaric pressurebelow a certain level in the socket. This may be achieved using asealing membrane or seal component between the residual limb and thesocket, instead of the conventional sealing method of using a sleeve toform an airtight connection between the residual limb and the proximalend of the socket. The sealing membrane may be on a prosthetic liner asdescribed in U.S. Pat. No. 8,034,120 incorporated by reference andbelonging to the assignee of this disclosure.

The benefit of using a liner having a seal or seal component reduces thevolume of air to be drawn out of the socket and therefore, a bettersuspension may be achieved in a shorter time period. Using a siliconeliner with integrated seal also provides the added benefit that thehypobaric region is not directly applied to the skin.

The vacuum pump mechanisms in the embodiments of the prosthetic devicedescribed are generally described as a pump mechanism. A bladder-typepump may be used in the embodiments in place of a membrane-type pump,and a skilled person would understand that the pump mechanisms describedmay also be used with a bladder-type pump and vice versa.

A bladder-type pump has an interior fluid chamber surrounded by anairtight material. When the interior chamber is expanded, the opposingwalls are moved away from each other by extending at least one side wallof the pump. The side walls of the bladder-type pump may have anaccordion-like shape or be formed of a polymeric material which allowfor the increase in distance between the opposing walls.

A membrane-type pump has at least one wall of flexible material and asecond opposing wall which may be rigid or flexible. The edges of thetwo walls are attached to each other such that when a force applies tothe pump to expand the interior fluid chamber, the force deforms atleast the flexible wall, and the flexible wall arcs outward to form aninterior fluid chamber. To allow for deformation, the flexible wall maybe made of a polymeric material including elastomeric material such asrubber or plastic.

The bladder-type pump and membrane-type pump are arranged so that whenno force applies to the pump or no weight is placed on the prostheticdevice the volume of the interior fluid chamber is zero or near-zero.The pumps described and shown have a cylindrical shape. A skilled personwould understand that the pumps may have a variety of shapes, forexample, a diamond, rectangular, or triangular shape.

The specific embodiments of the prosthetic device will now be describedregarding the figures.

First Embodiment of the Prosthetic Device

FIG. 1 shows a first embodiment of the prosthetic device comprising apump mechanism 2 and a prosthetic foot 4. The pump mechanism 2 has twoopposing walls and at least one side wall. The prosthetic foot 4 has anankle area 8, a heel area 10, and a movable member 12 attached at oneend to the prosthetic foot 4 and extending over the front of theprosthetic foot 4 leaving an unattached end. The attached end of themoveable member 12 may be pivoting or non-pivoting. The moveable member12 generally follows the curvature of the front of the prosthetic foot 4and a clearance between the moveable member 12 and the front of theprosthetic foot 4 gradually increases. The pump mechanism 2 is placed inthe clearance between the movable member 12 and the front of theprosthetic foot 4 within the ankle area 8 near the unattached end of themoveable member 12. One side of the pump is attached to the member 12and another side of the pump is attached to the prosthetic foot 4.

The pump mechanism 2 may be a bladder-type pump or a membrane-type pumpas discussed above. FIG. 1 shows the pump mechanism 2 as being abladder-type pump. The bladder-type pump may be formed of an elastomericmaterial such that the walls of the pump mechanism 2 can stretch whenopposing forces apply to the opposing walls of the pump mechanism 2.

When a user steps, such as a heel strike, weight is placed on the heelof the foot 4 and the moveable member 12 moves away from the foot 4pulling the attached wall and causing the volume of the internal fluidchamber of the pump mechanism 2 to increase. The increase in volume ofthe fluid chamber draws fluid into the interior fluid chamber. Duringthe stance phase or toe-off, the moveable member 12 compresses the pumpmechanism 2 decreasing the volume of the internal chamber and causingthe pump mechanism 2 to expel fluid within the fluid chamber. The pumpmechanism 2 may be fitted with one-way valves to control the directionof fluid flow so that fluid is not drawn from the atmosphere when thevolume of the internal chamber is increased, and the fluid is notexpelled into the socket when the pump mechanism 2 is compressed.

The vacuum pump mechanism 2 can be placed in various areas of theprosthetic foot 4 along the front of the foot. As shown in FIG. 2, themovable member 12 may be attached to the shin of the prosthetic foot 4and extend towards the pylon attachment point of the prosthetic foot 4.The moveable wall 12 is attached using a common foot attachment 20. Thevacuum pump mechanism 2 is similarly placed near the unattached end ofthe moveable member 12. In an embodiment as shown in FIG. 2, themoveable member 12 comprises a first piece 14 and a second piece 16connected at a non-pivoting joint 18. Using two pieces 14, 16 provides agreater overall range of distances between the wall and the prostheticfoot at the open end.

The moveable member 12 and pieces 14, 16 may be formed of many materialsincluding carbon fiber, plastic, and metal. The moveable member 12 maytake a variety of forms including a plate, wire, or arm.

In this embodiment, as used in others, the moveable member 12 connectsto the proximal end 5 of the prosthetic foot 4, whereat a connector 7carries a male pyramid adapter 9.

Second Embodiment of the Prosthetic Device

FIG. 3 shows another embodiment of the prosthetic device comprising avacuum pump mechanism 2 and a prosthetic foot 4. The vacuum pumpmechanism 2 in this embodiment is a membrane-type pump comprising aflexible membrane 22 and a rigid wall 24. The flexible membrane 22 formsa seal with the rigid wall 24. In FIG. 3, this seal may be formed byhaving the flexible membrane 22 extend over and around the edges of therigid wall 24 such that the rigid wall 24 fits within a recess formed bythe edges of the flexible membrane 22. An airtight seal between therigid wall 24 and the edges of the flexible membrane 22 may be formedusing an adhesive.

A moveable member 30 is attached at one end to the prosthetic foot 4 inthe midfoot area with a pivoting attachment 28, and the moveable member30 wraps around the heel area 10 of the foot 4. The portion of themoveable member 30 located within the heel area 10 maintains contactwith the heel portion of the foot 4 such that on a heel strike the heelportion of the foot 4 rotates the arm upward and pulls the rigid wall 24causing a deformation of the flexible membrane 22. Simultaneous to theupward movement of the moveable member 30, the ankle portion of the foot4 moves downwards.

The total deformation of the flexible membrane 22 combines thedisplacement of the rigid wall 24 caused by the upward movement of themoveable member 30 and the downward movement of the ankle portion towhich the flexible membrane 22 is attached. The flexible membrane 22 andrigid wall 24 are simultaneously pulled away from each other, and thedisplacement between the bottom of the flexible membrane 22 and therigid wall 24 corresponds to the displacement between ankle and heelportions of the prosthetic foot 4.

During displacement of the flexible membrane 22 and the rigid wall 24, afluid chamber is formed or the volume of an existing fluid chamber isincreased to draw in air through a one-way valve 26 by deforming theflexible membrane 22. In the embodiment in FIG. 3, the flexible membrane22 has a circular shape and is attached to the prosthetic foot at itscenter point while the edges of the flexible membrane 22 are firmlyattached to the rigid wall such that when the flexible membrane 22 andrigid wall 24 are pulled away from each other a pocket forms in themiddle of the flexible membrane due to the deformation of the flexiblemembrane 22.

Once weight is removed from the heel portion of the prosthetic foot 4,the flexible membrane 22 and rigid wall 24 move towards each other andfluid within the fluid chamber is expelled out of a one-way valve 26.

Third Embodiment of the Prosthetic Device

FIG. 4 shows another embodiment of the prosthetic device having aprosthetic foot 4 and a membrane-type vacuum pump mechanism 2. Themoveable member 30 in this embodiment is formed as a combination of twomoveable plates 32, 34. The top plate 32 is connected to the rigid wall24 and, in FIG. 4, is shown as extending through the rigid wall 24. Thebottom plate 34 is connected to the flexible membrane 22 near themembrane's attachment point 40 to the prosthetic foot 4. The bottomplate 34 is also attached to the front of the prosthetic foot 4 in theshin area of the foot 4. The bottom plate 34 follows the curve of thefoot 4 by having a substantially constant clearance between the bottomplate 34 and the foot 4. Near the midfoot and forefoot areas, theclearance between the bottom plate 34 and the foot 4 increases so thebottom plate 34 does not impede the gait of the user.

The top plate 32 is present between the ankle area and the midfoot areaof the foot 4 and is partially parallel to the bottom plate 34. The topplate 32 and the bottom plate 34 meet in the midfoot area and form afirm connection at a common attachment point. The top plate 32 has twoarms 42 which extend down each side of the foot 4 from the top plate 32to the heel area of the prosthetic foot 4. A heel cylinder 36 isconnected between the arms 42 and rests on the heel of the foot 4.

Similar to a previous embodiment, the vacuum pump mechanism 2 in theembodiment in FIG. 4 utilizes the displacement which occurs between theankle area and the heel area of the foot during a heel strike toincrease the volume of the fluid chamber within the vacuum pumpmechanism 2. When the heel strikes the ground, the heel of the foot 4presses on the heel cylinder 36 and causes the top plate 32 and rigidwall 24 to shift away from the front of the prosthetic foot 4. The ankleof the foot 4 is depressed causing the membrane fixed to the rigid wall24 and the foot 4 to be deformed expanding the fluid chamber within thepump mechanism 2.

The pump mechanism 2 can be arranged at a variety of points on the frontof the prosthetic foot in combination with different angles of the arms42 to maximize the length of the displacement between the stationaryposition of the pump and compressed position.

The membrane used in the embodiments described can vary in thickness indifferent areas and in shape. The thickness of the membrane may bethicker at the portions attached to the rigid wall to create a strongerconnection and greater deformation of the membrane wall. Similarly, themembrane wall may be thinner than the attachment portions to allow forgreater displacement with less force. The membrane may a cylindricalshape or a tapered shape as shown in FIG. 4B.

Fourth Embodiment of the Prosthetic Device

FIGS. 5A and 5B depict another embodiment of the prosthetic device. FIG.5A is a side view of the prosthetic device, and FIG. 5B is across-section of the embodiment in FIG. 5A.

The pump mechanism 2 in FIG. 5A comprises a flexible enclosure 44 and ahousing 46. The housing 46 has a semicircular shape having an open end.The interior wall of the housing 46 along the open end has anindentation for receiving the flexible enclosure 44, and the flexibleenclosure 44 forms a covering for the open end. The exterior wall of theflexible enclosure 44 is attached to the housing 46. An anchor member 48extending from the foot 4 through the housing 46 attaches to the otherside of the flexible enclosure 44.

Upon a heel strike, the interior wall is deformed due to stress placedon the edges of the interior wall and an interior fluid chamber isformed or expanded. The ankle and heel of the foot 4 compress thehousing 46 and shift the housing 46 outwards which causes the housing 46to push the edges of the flexible enclosure 44 outwards. Meanwhile, theanchor member 48 is firmly attached to the interior enclosure wall,preferably near the center of the interior enclosure wall, and since theinterior enclosure wall remains stationary, the outward movement ofhousing 46 causes at least the interior wall to deform and increase thevolume of an interior fluid chamber.

The compressive force on the housing 46 is provided along a first axis56, and the resulting expansion of the fluid chamber is along a secondaxis 58 substantially perpendicular to the first axis 56.

The anchor member 48 preferably ends with an arm plate 50 attached tothe interior enclosure wall. The arm plate 50 is semi-rigid so that oncethe compressive force is removed from the housing 46, the housing 46 andthe flexible enclosure 44 return to their unextended state which causesthe fluid drawn into the interior fluid chamber to be expelled.

The anchor member 48 may be attached to the interior wall using hooks oradhesive or some other form of mechanical connection. The arm plate 50may be provided with hooks which attached to the interior wall of theenclosure 44. The hooks may also fit within a groove along the interiorcircumference of the wall such that when the housing shifts outward thehooks remain in the groove causing the attachment point of the wall toremain stationary while the edges around the interior wall shiftoutward.

In another embodiment, the enclosure 44 is formed of two separateopposing walls. The opposing walls are attached to each other using amechanical connection such as a screw. A seal is formed between theopposing walls through the strength of the mechanical connection.

The flexible enclosure 44 is described as operating as a membrane-typepump, and a skilled person would understand that the flexible enclosure44 may also be in a bladder-type pump having a reciprocating wall.

Fifth Embodiment of the Prosthetic Device

FIG. 6 shows an embodiment of the prosthetic device using the pumpmechanism 2 of the embodiment in FIGS. 5A and 5B. In the embodiment ofFIG. 6, the pump mechanism 2 is attached on the front of the prostheticfoot 4 in the ankle area of the foot 4. The anchor member 48 wrapsaround a cylindrical block 52 and through the foot 4 to connect to thepump mechanism 2.

In this embodiment, the housing 46 remains stationary while thecylindrical block 52 is pushed outwards when weight applies to the heelof the foot 4. The interior flexible enclosure wall is pulled due to apulley effect create by the outward movement of the cylindrical block 52on the anchor member 48 to which the interior wall is attached. When theanchor member is pulled outwards, the interior wall flexes or deformsstarting at the attachment point of the interior wall and the anchormember to cause the interior fluid chamber to expand. For an embodimentusing a bladder pump, the interior wall may reciprocate within thehousing.

The anchor member may be a cable or wire made of a flexible materialsuch as an elastomeric material, metal, or plastic.

Sixth Embodiment of the Prosthetic Device

The sixth embodiment of the prosthetic device in FIGS. 7A-7C is similarto the third embodiment illustrated in FIGS. 4A and 4B. Elements similarbetween these embodiments are identified with the same referencenumerals.

The prosthetic foot 4 has a vacuum pump mechanism 65 attached to thefoot 4 through two plates 32, 34. The pump mechanism 65 is placed on atop surface of top plate 32 and operable between the two plates as shownin more detail in FIG. 7B. The pump mechanism 65 has a housing 66containing two one-way valves 68, 70, a membrane 22, and a membraneconnector 86. The valve 68 only allows fluid to enter the pump mechanism65 and is connected to a tube 72. Through the tube 72, the pumpmechanism 65 is in fluid communication with the cavity of the prostheticsocket. The tube 72 may be secured to the foot 4 with a tube attachment74. The other valve 70 only allows fluid to be expelled out of the pumpmechanism 65 preferably to atmosphere.

Similar to the third embodiment, upon a heel strike, the force on theheel of the foot 4 and a heel element 76 in the direction of arrow 96 inFIG. 7C relative to the foot flexes causes the top plate 32 to flex nearthe anterior end portion of the top plate 32 to pull the housing 66 awayfrom the membrane 22. When the housing 66 attached to the top plate 32pulls away from the membrane 22, the membrane 22 attached to the bottomplate 34 is deformed and an interior fluid chamber is formed pulling influid through valve 68. When the force from the heel strike is removed,the inherent properties of the material of the top plate 32 return thetop plate 32 to its unflexed state. During the return of the top plate32 to its unflexed state, the pump mechanism 65 expels fluid in thefluid chamber out of the valve 70. To meet the stiffness/flexibility,strength, and weight requirements needed for use on a prosthetic foot,the plates 32, 34 are made of a stiff but elastically bendable ordeformable material such as carbon fiber, plastic, or metal.

As discussed, the pump mechanism 65 relies upon deformation of amembrane 22 to increase the volume of a fluid chamber located betweenthe bottom surface of the housing 66 and the top surface of the membrane22. The housing 66 surrounds the outer edge of the membrane 22 andcreates an airtight seal with the membrane 22. The membrane andsurrounding portion of the housing 66 rest within an opening in the topplate 32. The housing 66 has a lip which extends beyond the membrane 22and surrounding portion of the housing to rest on the top surface of thetop plate 32 and allows the top plate 32 to pull the housing 66 awayfrom the membrane 22 when flexed.

The bottom surface of the housing 66 has two openings which extend intothe housing to form internal passageways 84 to provide fluidcommunication between the internal fluid chamber and the two one-wayvalves 68, 70. The bottom surface of the housing 66 complements the topsurface of the membrane 22 such that when no force is exerted on thepump mechanism 65 to expand the fluid chamber, the volume of the fluidchamber is zero or near-zero. As shown in FIG. 7B, both the bottomsurface of the housing 66 and the top surface of the membrane 22 arepreferably flat. The housing 66 may be formed of metal such as stainlesssteel or plastic or any other material which would provide sufficientstrength to resist deformation or damage when pulled away from themembrane 22.

The pump mechanism 65 may be easily removed and reattached with no toolsthrough a connector 86 on the membrane 22. The connector 86 is formed ofan insert 88 having a circular end embedded in the membrane 22 and afastener, such as a screw 90. The connector 86 anchors the membrane 22to the bottom plate 34. The screw 90 having a circular end is used withthe insert 88 to form the connector 86. The bottom plate 32 has twopartially overlapping circular openings. The first circular opening islarger than the circular end of the screw 90 while the second circularopening is smaller than the circular end of the screw 90. To fixedlyattach the pump mechanism 65 to the plates 32, 34 the screw 90 isinserted through the opening of the top plate 32 and then the firstopening of the bottom plate 34 such that the lip of the housing 66 restson the top plate 32. The user then slides the pump mechanism 65 into thesmaller second circular opening and snaps the pump mechanism 65 intoplace. The insert 88 and the screw 90 may be formed of metal. Throughthe structure of the pump mechanism 65 and the plates 32, 34, the pumpmechanism 65 has the benefit of being easily and quickly replaced.

The top plate 32 is provided with an opening 82 to enable easier flexionof the top blade near the attachment point 80. The size and shape of theopening 82 may be adjusted to change the force needed on the heel striketo flex the top plate 32. The attachment at attachment point 80 may bein a screw.

The heel element 76 is located between and attached to the two arms 42of the top plate 32 which extend down either side of the foot 4, and theheel element 76 rests on the heel portion of the foot 4. The heelelement 76 is preferably contoured such that the entirety of at leastthe outer edges of the bottom surface of the heel element 76 are incontact with the surface of the heel portion of the foot 4 upon whichthe heel element 76 rests. Through the contoured shape of the heelelement 76 and the length and material of the top plate 32 and its twoarms 42, the heel element 76 is held in place on the heel of the footwith no mechanical attachment between the heel element 76 and the heelof the foot.

To provide a lightweight pump mechanism 65 and pump mechanism on theprosthetic foot 4, the heel element 76 has an upper recess surrounded byraised edges 92. The raised edges 92 are formed such that the edges 92provide a supporting surface for the curved ankle area of the foot 4.The edges 92 also control the maximum flexion of the top plate 32 andtherefore, expansion of the pump mechanism 65.

As seen in FIGS. 7B and 7C, the raised edges 92 are contoured to receivethe ankle area of the foot upon a heel strike. The heel element 76 isfurther provided with a plurality of slots 78 which extend through theheel element 76 to reduce the weight of the heel element 76. The slots78 also allow particles or dirt to pass through the heel element 76 sothe particles do not become trapped between the heel element 76 and thefoot 4 and cause damage to the foot 4. The heel element 76 has a lowerrecess 94 on the bottom surface near the center which corresponds tospace between the two blades of the prosthetic foot which form the heel.

An insert, which may have an “H” shape (not shown), fits between theblades of the heel and extends between the lower recess 94 of the heelelement 76 and the blades of the heel. The insert may be formed ofrubber and is used to provide a uniform pressure distribution from theheel of the foot 4 to the heel element 76. If the force on heel strikeis only placed on one blade of the heel, some force is distributed tothe other side and blade of the heel.

The embodiments described may be used with a prosthetic socket asdescribed in U.S. Pat. No. 6,589,289 incorporated by reference andbelonging to the assignee of this disclosure.

The embodiments described may be used with a prosthetic foot asdescribed in U.S. Pat. No. 6,969,408 incorporated by reference andbelonging to the assignee of this disclosure.

FIG. 8 illustrates a prosthetic device or a vacuum suspension system 100including the pump mechanism 65 of FIG. 7A. The vacuum suspension systemhas a socket 102, a liner 104 preferably including a seal component 106,a valve 108, a tube 110 connecting the pump mechanism 65 to the socket102, and a prosthetic foot 114. The socket defines an interior space103, and interior walls 105 delimiting the interior space. The vacuumsuspension system 100 may also employ a shock and/or rotation module112. The shock and/or rotation module may be replaced with the connectorand adapter system under the embodiment of FIG. 1.

The vacuum suspension system 100 provides improved proprioception andvolume control. The vacuum suspension system 100 includes the pumpmechanism 65, as discussed in earlier embodiments, which provides avacuum assisted suspension by generating a negative pressure (vacuum)inside the socket 102. The function of the vacuum suspension system isfully automatic. The weight of the user is placed on the heel of theprosthetic foot 114 and expands the vacuum pump to efficiently draw airout of the socket in each step and expel it into the atmosphere duringswing phase as the reservoir compresses again. The pump mechanism 65creates a negative pressure inside the socket, resulting in a secure andreliable elevated vacuum suspension. The vacuum assisted suspensionresults in a secure and intimate suspension as the negative pressureformed inside the socket 102 within a vacuum zone 107 holds the liner104 and the residuum firmly to the socket wall.

The vacuum suspension system 100 in combination with the liner 104having a seal component 106 preferably at the proximal portion of theline allows for a transtibial amputee to move freely without pulling onthe knee joint. This provides better comfort during daily activities andwhen sitting or driving.

The liner 104 may be of type including a seal component, preferably theliner with a seal component described in U.S patent applicationpublication no. 2013/0053982, published on Feb. 28, 2013, incorporatedby reference, and sold as the ICEROSS SEAL-IN V LINER by Össur hf. Otherliners having a seal component may likewise be used including linersdisclosed in U.S. Pat. No. 7,025,793, granted on Apr. 11, 2006, U.S.Pat. No. 7,909,884, granted on Mar. 22, 2011, U.S. Pat. No. 8,034,120,granted on Oct. 11, 2011, U.S. Pat. No. 8,052,760, granted on Nov. 8,2011, U.S. Pat. No. 8,097,043, granted on Jan. 17, 2012, and U.S. Pat.No. 8,956,422, granted on Feb. 17, 2015. Each of these references isincorporated by reference. The vacuum suspension system is not limitedto the liners mentioned above, and other liners whether with or withouta seal may be employed.

The shock absorption from the rotation/shock module is independent ofthe pump module 4 which harvests a small amount of the heel motion forefficient vacuum generation. A rotation/shock module useable with thevacuum suspension system 100 is found in at least U.S. Pat. No.6,478,826, granted on Nov. 12, 2002, U.S. Pat. No. 6,969,408, granted onNov. 29, 2005, and U.S. Pat. No. 7,371,262, granted on May 13, 2008,incorporated by reference and belonging to the assignee of thisdisclosure. A commercial example of the foot and shock module may be theRE-FLEX SHOCK or RE-FLEX ROTATE sold by Össur hf of Reykjavik, Iceland.

FIGS. 9 and 10 illustrate an embodiment of the valve 108 for the vacuumsuspension system 100. As shown in FIGS. 11A-11C, the valve 108 may beconsidered a tri-function valve in that it permits expulsion, vacuumbypass, and release.

FIG. 10 shows the valve 108 as having a cap or release button 118 andspring 120 inserted into a valve core 122, and interlocked by insertinga first o-ring or gasket 124 onto a smaller end of the release button118 as it protrudes from the valve core 122. The cap key 116 is used toscrew on or off the cap or release button 118 for checking the partswithin the valve. A membrane 126 is inserted into an interior groove 152formed on the valve core 122. A valve foam air filter 128 is insertedinto a groove on a valve inner housing 130. The valve core 122 and thevalve inner housing 130 are fastened to one another.

A second ring or gasket 132 and a third ring or gasket 134 are insertedinto an interior groove 154 on a valve outer housing 136. A check valve144 is inserted into an aperture 156 on the valve outer housing 136 andis interlocked with a tube connector 146.

The valve foam 138, screw 140 and valve insert 142 are used for mountingthe valve 108 onto a socket. While the valve foam 138 and screw 140 maybe removed after the socket is formed, the valve insert 142 remains onthe socket and is used for coupling the valve 108 thereto. The shaft 148of the valve inner housing 130 extends through an opening 158 of thevalve insert 142 and into the socket 102 for fluid communicationtherewith for forming the vacuum.

The valve inner housing 130 is inserted into the valve outer housing136. This arrangement of the valve outer housing 136 in combination withthe gaskets used therewith is that the valve inner housing 130 andassociated parts can be tightened or rotated regardless of the directionof the valve outer housing 136. The valve outer housing 136 can rotaterelative to the socket with no loss of vacuum. This allows foraccommodating any movement from the tube 110 coupled to the pump module4 and the prosthetic foot 114.

As exemplified in FIGS. 11A-11C, FIG. 11A shows how the valve 108permits expulsion of air through apertures 150 formed within the valvecore 122, with air entering through the shaft 148, and exiting throughthe apertures 150. This arrangement allows the valve 108 to easily expelair from within the socket, for example, when the socket is donned.

FIG. 11B shows the valve 108 when it serves as a vacuum bypass. In thisconfiguration, the air is expelled from the socket through the shaft 148and is draw (by vacuum) through the tube connecter 146 and check valve144. The check valve 144 can maintain an airtight even if the tubeconnecting the pump module to the socket fails.

FIG. 11C shows an embodiment where pressing the release button 118 letsair into the socket and releases the vacuum, for example, so that thesocket can be doffed. In this embodiment, the air enters through theapertures 150 and channels through the shaft 148 to introduce air intothe socket.

Seventh Embodiment of the Prosthetic Device

FIG. 12 illustrates another embodiment of a pump mechanism 67 mounted onyet another different prosthetic foot 4. According to this embodiment,the prosthetic foot 4 includes a plate-like foot member 75 attached to aresilient heel member 77. A top mount 79 extends over the resilient heelmember 77, and carries an adapter 9. An example of the prosthetic footis described in greater in U.S. Pat. No. 8,961,618, granted Feb. 24,2015, and commercially available as the FLEX-FOOT BALANCE by Össur hf.This patent is incorporated by reference and belongs to the assignee ofthis disclosure.

As shown in FIGS. 13A and 13B, the pump mechanism 67 is rocked back andforth as the foot plate 75 heel strikes (FIG. 13A) and toe strikes(13B). During a heel strike, as depicted in FIG. 13A, the membrane 22 isin a relaxed position and draws no vacuum from the socket via the tube72. The one-way valve 70 only permits expulsion of air from the pumpmechanism. During a toe strike, as depicted in FIG. 13B, the membrane 22expands as it is pulled away from the top mount 79, and draws a vacuum(as evidenced by the arrow), whereas the air is expelled from the valve70.

One will understand that the vacuum of this embodiment can be oppositeof that of the embodiment depicted in FIGS. 7A-7C. In particular, FIGS.13A-13B depict an embodiment where air is drawn out of the socket duringa toe strike (FIG. 13B). In contrast, FIGS. 7A-7C depict an embodimentwhere air is drawn out of the socket during a heel strike.

In FIGS. 13A-13B, the membrane 22 is mounted under a plate section 166of a rocker device 160. The rocker device 160 includes a bumper 162 at afirst end and arranged for engaging the foot plate 75 at various phasesof a walker's gait. A limiter 178 is provided under the plate section tolimit rocking of the plate section 166. As the bumper 162 strikes thefoot plate 75, an arm 164 extending from the bumper 162 and connectingto the plate section 166 causes the plate section 166 to draw away fromthe top mount 79. As the bumper 162 strikes the foot plate 75, an arm164 extending from the bumper 162 and connecting to the plate section166 causes the plate section 166 to draw away from the top mount 79.

FIG. 14 depicts the membrane 22 as having a coupling 168 with anaperture 174 and arranged to engage a pin 172 having an aperture 176,whereas the coupling 168 and pin 172 are retained by a spring lock 170.The coupling 168 is sized to permit pivoting of the pump mechanism 67relative to the top mount 79.

The embodiments described may be used with a pressure regulator toinsure the safety and comfort of the user which may be achieved usingmechanical and/or electronic methods known in the industry.

While the foregoing embodiments have been described and shown,alternatives and modifications of these embodiments, such as thosesuggested by others, may be made to fall within the scope of theinvention. The principles described may be extended to other types ofprosthetic or orthopedic devices.

The invention claimed is:
 1. A prosthetic system comprising: a pumpmechanism operatively connectable to a prosthetic foot, the pumpmechanism including: a housing defining first and second ports; amembrane having an outer edge portion secured to the housing; a fluidchamber with a volume defined between the housing and a first side ofthe membrane, the fluid chamber in fluid communication with the firstand second ports; a connector attached to a second side of the membraneopposite the first side of the membrane, the connector operativelyconnecting the membrane to the prosthetic foot such that when no weightis placed on the prosthetic foot the volume of the fluid chamber is zeroor near-zero and when weight of a user is placed on the prosthetic footduring a heel strike the membrane deforms to expand the volume of thefluid chamber.
 2. The system of claim 1, wherein the housing surroundsthe outer edge portion of the membrane and creates an airtight seal withthe membrane.
 3. The system of claim 2, wherein the connector isattached to a central portion of the membrane defined radially inside ofthe outer edge portion of the membrane.
 4. The system of claim 3,wherein the weight of the user applied to the prosthetic foot causes thecentral portion of the membrane to pull away from the housing toincrease the volume of the fluid chamber.
 5. The system of claim 3,wherein the weight of the user applied to the prosthetic foot causes thehousing to pull away from the central portion of the membrane toincrease the volume of the fluid chamber.
 6. The system of claim 1,wherein the first side of the membrane is substantially flat and abottom surface of the housing engages and substantially complements thefirst side of the membrane.
 7. The system of claim 1, wherein theconnector includes an insert embedded in the membrane.
 8. The system ofclaim 7, wherein the insert has a circular end embedded in the membraneand a fastener.
 9. The system of claim 1, further comprising a tubeconnected to the first port.
 10. The system of claim 9, wherein thefirst port is arranged to draw fluid through the tube dues to theincrease of volume of the fluid chamber.
 11. The system of claim 1,wherein at least one of the first and second ports includes a one-wayvalve.
 12. The system of claim 1, wherein the pump mechanism ispositioned along a dorsal aspect of the prosthetic foot.
 13. The systemof claim 1, wherein the prosthetic foot includes a foot member and aheel member attached to the foot member, and wherein the housing issecured to a first plate member engagable with the heel member and theconnector is securable to a second plate member attachable to the firstplate member and the foot member.
 14. The system of claim 13, whereinthe pump mechanism is operable between the first and second platemembers.
 15. The system of claim 13, wherein the housing includes a lipportion extending radially beyond the membrane and arranged to rest on atop surface of the first plate member.